It's not all bad. Things to look for:
- Handbrake noises/adjustment. Properly adjusted they are no problem, but most dealers don't seem to take time or know how to do it. If left badly adjusted the electric motor assembly will strip gears and need replacing, fuel tank had to come out.
- EGR valves will fail, check they have been done on older cars.
- Stay away from manuals in D3, the clutch is too weak, outs cost £1100 to replace at circa 26k.
- Suspension bushes wear, check for work having been already done under warranty on cars around 3 years.
- check tyre tread. New set boots is not cheap.
- Check spare is present under rear and that winch to lower it works. Early ones had few issues but they are fine until someone is heavy handed with them.
All electric trickery never have ius a single issue, it's the basic mechanics that failed for our D3 experience.
Now for some positives:
- Great visibility and driving experience.
- Massive lead carrying both volume and weight.
- third row seats perfect for mother in law.
- Crash safety of a modern car.
- Economy in low 30's if your not lewis Hamilton.
I found it easy to work on just a bit scaled up! Changed rear pads and front discs and pads on ours no problem. Parts from friendly dealers are not expensive, jobs not add complicated as you expect, had typo change motor on drivers central locking and was simple.
Oh finally air filtering change internal is stupid, like 3 years or something. If you buy second hand put a new one on, £20 or so from main dealer, they clog up in time and affect performance and economy.
The dedicated disco forum is best for all technical info...
TallPaul